new module 'mbschr'

[Bruno Haible]

This adds a new module, a variant of strchr() that works in multibyte locales.

2007-02-04  Bruno Haible  <address@hidden>

        New module mbschr.
        * modules/mbschr: New file.
        * lib/mbschr.c: New file.
        * lib/string_.h (strchr): Add a conditional link warning.
        (mbschr): New declaration.
        * m4/mbschr.m4: New file.
        * m4/string_h.m4 (gl_STRING_MODULE_INDICATOR_DEFAULTS): Initialize
        GNULIB_MBSCHR.
        * modules/string (string.h): Also substitute GNULIB_MBSCHR.
        * MODULES.html.sh (Internationalization functions): Add mbschr.

========================== modules/mbschr =================================
Description:
mbschr() function: search a string for a character.

Files:
lib/mbschr.c
m4/mbschr.m4
m4/mbrtowc.m4

Depends-on:
mbuiter
string

configure.ac:
gl_FUNC_MBSCHR
gl_STRING_MODULE_INDICATOR([mbschr])

Makefile.am:
lib_SOURCES += mbschr.c

Include:
<string.h>

License:
LGPL

Maintainer:
Bruno Haible

=========================== lib/mbschr.c ==================================
/* Searching a string for a character.
   Copyright (C) 2007 Free Software Foundation, Inc.
   Written by Bruno Haible <address@hidden>, 2007.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include <config.h>

/* Specification.  */
#include <string.h>

#if HAVE_MBRTOWC
# include "mbuiter.h"
#endif

/* Locate the first single-byte character C in the character string STRING,
   and return a pointer to it.  Return NULL if C is not found in STRING.  */
char *
mbschr (const char *string, int c)
{
#if HAVE_MBRTOWC
  if (MB_CUR_MAX > 1
      /* Optimization: We know that ASCII characters < 0x30 don't occur as
         part of multibyte characters longer than 1 byte.  Hence, if c < 0x30,
         the faster unibyte loop can be used.  */
      && (unsigned char) c >= 0x30)
    {
      mbui_iterator_t iter;

      for (mbui_init (iter, string);; mbui_advance (iter))
        {
          if (mb_len (mbui_cur (iter)) == 1
              && (unsigned char) * mbui_cur_ptr (iter) == (unsigned char) c)
            break;
          if (!mbui_avail (iter))
            goto notfound;
        }
      return (char *) mbui_cur_ptr (iter);
     notfound:
      return NULL;
    }
  else
#endif
    return strchr (string, c);
}
=========================== m4/mbschr.m4 ==================================
# mbschr.m4 serial 1
dnl Copyright (C) 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_MBSCHR],
[
  gl_PREREQ_MBSCHR
])

# Prerequisites of lib/mbschr.c.
AC_DEFUN([gl_PREREQ_MBSCHR], [
  AC_REQUIRE([gl_FUNC_MBRTOWC])
  :
])
===========================================================================
--- MODULES.html.sh     1 Feb 2007 17:22:52 -0000       1.180
+++ MODULES.html.sh     5 Feb 2007 00:56:22 -0000
@@ -2161,6 +2161,7 @@
   func_module iconvme
   func_module localcharset
   func_module hard-locale
+  func_module mbschr
   func_module mbswidth
   func_module memcasecmp
   func_module memcoll
--- lib/string_.h       3 Feb 2007 00:01:56 -0000       1.7
+++ lib/string_.h       5 Feb 2007 00:56:22 -0000
@@ -148,6 +148,15 @@
      strncasecmp (a, b))
 #endif
 
+#if defined GNULIB_POSIXCHECK
+/* strchr() does not work with multibyte strings if the locale encoding is
+   GB18030 and the character to be searched is a digit.  */
+# undef strchr
+# define strchr(s,c) \
+    (GL_LINK_WARNING ("strchr cannot work correctly on character strings in 
some multibyte locales - use mbschr if you care about internationalization"), \
+     strchr (s, c))
+#endif
+
 /* Find the first occurrence of C in S or the final NUL byte.  */
 #if @GNULIB_STRCHRNUL@
 # if ! @HAVE_STRCHRNUL@
@@ -295,6 +304,20 @@
 # define strtok_r 
strtok_r_is_unportable__use_gnulib_module_strtok_r_for_portability
 #endif
 
+
+/* The following functions are not specified by POSIX.  They are gnulib
+   extensions.  */
+
+#if @GNULIB_MBSCHR@
+/* Locate the first single-byte character C in the character string STRING,
+   and return a pointer to it.  Return NULL if C is not found in STRING.
+   Unlike strchr(), this function works correctly in multibyte locales with
+   encodings such as GB18030.  */
+# define mbschr rpl_mbschr /* avoid collision with HP-UX function */
+extern char * mbschr (const char *string, int c);
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif
--- m4/string_h.m4      1 Feb 2007 05:01:17 -0000       1.5
+++ m4/string_h.m4      5 Feb 2007 00:56:22 -0000
@@ -70,4 +70,5 @@
   GNULIB_STRSTR=0;      AC_SUBST([GNULIB_STRSTR])
   GNULIB_STRCASESTR=0;  AC_SUBST([GNULIB_STRCASESTR])
   GNULIB_STRTOK_R=0;    AC_SUBST([GNULIB_STRTOK_R])
+  GNULIB_MBSCHR=0;      AC_SUBST([GNULIB_MBSCHR])
 ])
--- modules/string      1 Feb 2007 05:01:17 -0000       1.4
+++ modules/string      5 Feb 2007 00:56:22 -0000
@@ -21,6 +21,7 @@
        rm -f address@hidden $@
        { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
          sed -e 's|@''ABSOLUTE_STRING_H''@|$(ABSOLUTE_STRING_H)|g' \
+             -e 's|@''GNULIB_MBSCHR''@|$(GNULIB_MBSCHR)|g' \
              -e 's|@''GNULIB_MEMMEM''@|$(GNULIB_MEMMEM)|g' \
              -e 's|@''GNULIB_MEMPCPY''@|$(GNULIB_MEMPCPY)|g' \
              -e 's|@''GNULIB_MEMRCHR''@|$(GNULIB_MEMRCHR)|g' \